The present invention is related to image processing and, in particular, to an apparatus and method for recording digital still images on a data storage medium (e.g., a floppy disk) based on moving images reproduced from a digital VTR (Video Tape Recorder), for example.
In recent years, microprocessor-controlled devices, such as personal computers, have become very popular and widespread around the world. A personal computer may, for example, be used for displaying image data, captured from an outside source (a video camera), on a monitor device connected to the computer. Various processing operations may then be performed on the captured image data utilizing image processing software, for example.
Further, household use of digital VTRs (including digital camcorders) capable of recording and playing back moving picture image information has become widespread. The digital VTRs are capable of obtaining higher quality pictures than analog VTRs, that is VTRs for recording and reproducing analog image signals. Hence, it appears logical that an image obtained and/or played back by a digital video camera/digital VTR be captured by a computer and processed for various types of recreational or business use.
An obstacle, however, exists in such processing of images produced by the digital VTR. Namely, when an image reproduced from the digital VTR is supplied to the computer, the digital image signal has to be converted to an analog image signal. This analog image signal is then converted back to the digital form by the computer, and an image file is created in accordance with the appropriate video signal format. The thus obtained image file is recorded and stored on a recording medium, such as a hard disk or a floppy disk.
The reason for performing these seemingly unnecessary transformations (from digital to analog and back to digital domains) is as follows: the digital VTR records/reproduces the digital image using a special recording/reproducing format that is not compatible with display/manipulation of the digital images (in units of picture frames, for example) by the computer. Hence, the image represented by a digital signal is typically converted to an analog signal (represented as picture frames) to be captured by the computer prior to its processing operations. It is apparent that these conversions between analog and digital domains negatively affect picture quality.